Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 051825 AAB
AFDBRO

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1225 PM CST THU MAR 5 2015

.DISCUSSION...HIGH PRESSURE BUILDING FARTHER SOUTH THEN EXPECTED
HAS ALLOW FOR DRIER AIR TO WORK ITS WAY SOUTH. MUCH OF THE
PRECIPIATION HAS ENDED WITH EXCEPTION TO A FEW SPRINKLES OVER THE
VALLEY AND THE GULF WATERS. COLD AIR ADVECTION CONTINUES BUT WITH
NO RAIN AND HIGHER CLOUD DECKS TEMPERATURES TO HOLD STEADY THE
REST OF THE DAY. AS THE CENTER OF HIGH PRESSURE EDGES CLOSER TO
THE VALLEY THE PRESSURE GRADIENT CONTINUES TO WEAKEN. ALTHOUGH
STILL WINDY...THIS AFTERNOON THE WIND ADVISORY HAS BEEN
CANCELLED. ALSO, LESS WIND AND NOT AS COLD TEMPERATURES WILL KEEP
WIND CHILLS JUST ABOVE ADVISORY CRITERIA SO THE WIND CHILL
ADVISORY HAS BEEN CANCELLED AS WELL.

&&

.PREV DISCUSSION... /ISSUED 634 AM CST THU MAR 5 2015/

DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.

AVIATION...THE CAA IN THE WAKE OF THE FROPA EARLIER THIS MORNING
WILL MAINTAIN A STRONG AND SATURATED INVERSION THROUGHOUT TODAY
AND TONIGHT ACROSS THE RGV. EXPECT IFR CONDITIONS TO PREVAIL FOR
THE MOST PART THIS MORNING WITH CONDITIONS IMPROVING SLIGHTLY THIS
AFTERNOON REACHING MVFR LEVELS. THE CEILINGS WILL THEN LIKELY
FLUCTUATE BETWEEN MVFR AND IFR CONDITIONS THIS EVENING INTO THE
OVERNIGHT HOURS AS A LITTLE DRIER AIR FILTERS INTO THE REGION AT
THE LOWER LEVELS OF THE ATMS FROM THE NORTH.

PREV DISCUSSION... /ISSUED 423 AM CST THU MAR 5 2015/

SHORT TERM /NOW THROUGH FRIDAY/...THE FRONT HAS CLEARED THROUGH ALL
OF DEEP SOUTH TEXAS WITH STRONG NORTH WINDS FILTERING IN BEHIND THE
FRONT USHERING IN CAA ACROSS THE AREA. SURFACE OBS INDICATE THAT
TEMPS HAVE ALREADY FALLEN INTO THE 40S ACROSS THE AREA. WITH THE
STRONG NORTHERLY FLOW MAINTAINING STEADY CAA THROUGHOUT THE DAY DO
NOT EXPECT THE TEMPS TO REBOUND MUCH TODAY WITH STEADY OR NEAR
STEADY TEMPS PREVAILING THROUGHOUT THE DAY.  THE CAA WILL CONTINUE
ON THROUGH TONIGHT INTO FRI AS THE NORTHERLY SURFACE FLOW LINGERS
INTO TOMORROW. SOME DRIER AIR WILL BE FILTERING INTO THE REGION FROM
THE NORTH BUT DO NOT EXPECT ENOUGH DRY AIR TO REACH THE RGV TO
FINALLY CLEAR OUT THE LOW AND MID LEVEL MOISTURE VALUES. SO EXPECT
PLENTY OF CLD COVER TO PERSIST OVER THE AREA INTO TONIGHT AND
FRIDAY. SCT POCKETS OF PVA AT THE 500 MB LEVEL MOVING OVER THE AREA
FROM THE WEST WILL ALSO MAINTAIN THE POTENTIAL FOR LIGHT RAIN OR
DRIZZLE ON THROUGH TOMORROW ESPECIALLY NEAR THE COASTLINE. THERE
WILL BE A SMALL WINDOW OF OPPORTUNITY FOR SOME PATCHY FREEZING
DRIZZLE LATE TONIGHT THROUGH FRI MORNING AS THE CAA LOWERS THE TEMPS
DOWN TO JUST ABOVE OR NEAR FREEZING AT THE SURFACE. THE POTENTIAL
FOR SOME EVAPORATIVE COOLING MAY RESULT IN SOME POSSIBLE PATCHY
FREEZING DRIZZLE DURING THE OVERNIGHT HOURS. AT THIS TIME EXPECT
ONLY SOME POSSIBLE VERY LIGHT ACCUMULATIONS ON BRIDGES AND
OVERPASSES LATE THURS AND EARLY FRI.

FOR TEMPS WILL BE UNDERCUTTING ALL MODEL GUIDANCE FOR HIGHS AND LOWS
THROUGH FRI DUE TO THE ADDITIONAL COOLING IMPACTS FROM THE CLD COVER
AND PCPN POTENTIAL.

VERY LOW WIND CHILL VALUES IN THE 20S WILL PERSIST ON THROUGH
TONIGHT AND EARLY FRI AND WILL ACCORDINGLY EXTEND THE WIND CHILL
ADVISORY ON THROUGH MIDMORNING FRI.

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...THE FORECAST PERIOD
BEGINS WITH SOUTHWEST FLOW ALOFT AND A 500MB LOW OVER BAJA
CALIFORNIA AND NORTHWEST MEXICO. THIS WILL RESULT IN OVERRUNNING
CONDITIONS ACROSS DEEP SOUTH TEXAS...PERSISTENT CLOUDY SKIES WITH
PATCHY DRIZZLE AND LIGHT RAIN...FRIDAY NIGHT INTO SATURDAY MORNING.
AT THE SURFACE...CAA WILL CONTINUE ACROSS THE REGION THROUGH
SATURDAY AS SURFACE HIGH PRESSURE PREVAILS OVERHEAD. TEMPERATURES
WILL REMAIN WELL BELOW NORMAL THROUGH THE WEEKEND. LOW TEMPERATURES
FRIDAY NIGHT WILL GENERALLY RANGE FROM THE UPPER 30S ACROSS THE
NORTHERN RANCHLANDS TO THE LOW TO MID 40S NEAR THE COAST.

HIGH TEMPERATURES SATURDAY WILL CLIMB INTO THE 50S TO AROUND 60 NEAR
THE COAST. WILL MAINTAIN A SLIGHT CHANCE OF RAIN ACROSS THE GULF
WATERS AND ALONG THE COAST FOR SATURDAY. RAIN CHANCES INCREASE
SATURDAY NIGHT DUE TO THE DEVELOPMENT OF A COASTAL TROUGH OFF THE
LOWER TEXAS COAST AND WITH AN APPROACHING A 500MB TROUGH. LOW
TEMPERATURES SATURDAY NIGHT WILL RANGE FROM THE 40S ACROSS THE
RANCHLANDS TO THE LOWER 50S NEAR THE COAST. A SLOW WARMING TREND
WILL CONTINUE SUNDAY INTO THE EARLY NEXT WEEK...WITH NEAR NORMAL
TEMPERATURES RETURNING AROUND TUESDAY. RAIN CHANCES CONTINUE SUNDAY
THROUGH TUESDAY NIGHT AS THE MID LEVEL TROUGH IS SLOW TO MOVE EAST.
DRIER CONDITIONS CAN BE EXPECTED ON WEDNESDAY WITH HIGH TEMPERATURES
IN THE 70S...EXCEPT UPPER 60S ALONG THE COAST.

MARINE /NOW THROUGH FRIDAY/...CURRENTLY BUOY020 REPORTS A NORTH
WIND AT 29G37KTS WITH SWELLS AT 9 FT. THE STRONG POST FRONTAL PGF
WILL MAINTAIN NEAR GALE FORCE WINDS ON THROUGH TODAY WITH THE
GRADIENT STARTING TO DECREASE LATER TONIGHT. SCAS WILL LIKELY BE
NEEDED TO REPLACE THE GALE WARNINGS AS THE PGF DIMINISHES LATER
TONIGHT WITH SCA CONDITIONS CONTINUING ON INTO FRI.

FRIDAY NIGHT THROUGH MONDAY NIGHT...WINDS WILL CONTINUE TO DIMINISH
TO AROUND 10 KNOTS FRIDAY NIGHT INTO SATURDAY MORNING AS THE
PRESSURE GRADIENT RELAXES. HOWEVER...EXERCISE CAUTION TO LOW END
SMALL CRAFT ADVISORY CONDITIONS WILL BE POSSIBLE FRIDAY NIGHT DUE TO
ELEVATED SEAS OVER THE GULF WATERS. HIGH PRESSURE ACROSS THE
NORTHERN GULF WILL MAINTAIN LIGHT TO MODERATE NORTHEAST TO EAST
WINDS AND LOW TO MODERATE SEAS SATURDAY INTO SUNDAY. A LOW PRESSURE
TROUGH WILL DEVELOP OFF THE LOWER TEXAS COAST MONDAY. THIS WILL
RESULT IN NORTHEAST WINDS INCREASING AND SEAS BUILDING 5 TO 7 FEET
OVER THE GULF WATERS MONDAY. EXERCISE CAUTION OR LOW END SMALL CRAFT
ADVISORY CONDITIONS LIKELY ON THE GULF WATERS EARLY NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  44  37  47  44 /  40  20  10   0
BROWNSVILLE          42  35  46  42 /  40  20  10   0
HARLINGEN            42  33  45  40 /  40  20   0   0
MCALLEN              40  33  46  39 /  30  10   0   0
RIO GRANDE CITY      41  36  47  38 /  10  10   0   0
SOUTH PADRE ISLAND   46  40  49  47 /  40  20  10   0

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...GALE WARNING UNTIL 6 PM CST THIS EVENING FOR GMZ130-132-135-150-
     155-170-175.

&&

$$

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